Bungie will be making some substantial changes in how loot drops work for crucible players with the release of House of Wolves this May.

As reported by IGN today:

• Completed matches in crucible will now be worth 6 marks instead of the current 3, allowing players to earn mid-tier gear a lot faster.
• Bungie will also be increasing the number of rare drops available to Crucible players – we should be seeing a lot more blue and even some purple drops from PVP!
• Players will receive one etheric light (used to upgrade exotics) after hitting levels 3 or 5 in the Iron Banner Challenge.
• Xur the notorious vender who appears during the weekend will no longer be used to upgrade exotic gear. Instead all upgrades will be handled via etheric light drops.
• Players who place first in PVP matches will be more likely to receive decent drops.

The source article also has some pretty cool quotes from members of the development team as well!